a) Field of the Invention
The present invention relates to an overheating destructive conductive plate safety clip as well as a plug and a socket using that conductive plate safety clip. The overheating destructive conductive plate safety clip enables two conductive plates to be limited from contacting with each other, forming a closed path. In addition, the overheating destructive conductive plate safety clip is destructed when overheating, which enables the two conductive plates to be opened with respect to each other by an elastic force, forming an open circuit. The overheating destructive conductive plate safety clip is formed by combining metal with plastic, forming a destruction part. The destruction part is assured to be destructe completely using the advantage that metal is provided with a good thermal conductivity.
b) Description of the Prior Art
To prevent a circuit from current overloading, short-circuit or overheating, the circuit will be usually provided with a fuse or a breaker. When the circuit temperature is too high or the current is too large, the fuse will be melted down by high temperature or the metal spring leaves of the breaker will be ejected, which forms an open circuit to power off the circuit, thereby securing the safety in using electricity.
A Taiwanese Utility Model Patent No. M477079, “Overheat Failure Safety Structure and a Plug and a Socket with Overheat Failure Safety Structure,” has disclosed an insulative limiting element which connects two conductive elements to form a closed path. When the circuit is overheated, the insulative limiting element will be melted and broken, enabling the two conductive elements to be opened with respect to each other by an elastic force to form an open circuit. The limiting element is provided with a first insulative part and an opposite second insulative part. A connecting part is used to connect the first insulative part with the second insulative part, forming a U-shaped appearance and having an open end. The two conductive elements are clamped tightly at the open end.
Upon practically using that patent, the present inventor has found out that as the U-shaped limiting element may not have sufficient rigidity of combination; even the closed path between the two conductive elements is not overheated, the binding force of the U-shaped limiting element can be still reduced due to heat-up and the limiting element can be ejected off by the elastic force between the two conductive elements, thereby forming an open circuit between the two conductive elements. On the other hand, when the temperature between the two conductive elements is too high, the first insulative part and the second insulative part of the U-shaped limiting element will be ejected off by the elastic force between the two conductive elements. However, as the connecting part is still connected at the first insulative part and the second insulative part, the U-shaped limiting element will maintain a part of the binding force, so that the two conductive elements will keep partly contact, thereby being unable to power off the circuit completely. All the two situations described above are the possible false actions.
Furthermore, another Taiwanese Utility Model Patent No. M509999, “Overheating Destructive Insulative Fixing Plate as well as a Plug and a Socket Using that Insulative Fixing Plate,” has disclosed an overheating destructive insulative fixing plate, which includes a connecting element and two limiting elements combined at two ends of the connecting element to form an H-shaped structure. The connecting element is put into the grooves formed on two conductive elements, enabling the two limiting elements to be abutted at an exterior side of the conductive element respectively and limiting the two conductive elements from contacting with each other. The connecting element is destructed when overheating, forming an open circuit between the two conductive elements.
However, upon practically using that patent, the present inventor has found out that as the two limiting elements are all made of plastic, if the plastic material is not chosen properly, the heat conduction effect will be inferior. When the connecting element is softened by heat to reduce the binding force, the two limiting elements will be ejected off by the elastic force between the two conductive elements. At this time, as the heat conduction effect of the two limiting elements is reduced, the connecting element may not be destructed completely that the two limiting elements can contact with each other intermittently, so that the conductive elements may keep partly contact, thereby being unable to power off the circuit completely.